Anatomy Systema Respiratorium : Trachea et bronchus

Summary

The video provides an in-depth overview of the respiratory tract, specifically focusing on the trachea, bronchi, and bronchioles. It covers the anatomical divisions and structures of the respiratory system, highlighting the trachea's role as a conduit to the lungs and its bifurcation into the primary bronchi. The discussion includes details on the cartilaginous support of the trachea, the vascular and nerve supply, and the structural differences between the right and left primary bronchi. The video concludes by explaining the branching of bronchioles and their transition into respiratory zones, ending with the alveoli.

Takeaways

• 🫁 The respiratory tract is structurally divided into the upper and lower parts; the trachea is part of the upper tract.
• 🔄 Functionally, the trachea serves as a conducting zone, transporting air to the lungs.
• 📏 The adult trachea is about 11.25 cm long with a diameter of 2.5 cm, while in infants, it is around 4-5 cm long with a 3 mm diameter.
• 🛡 The trachea is supported by 16-20 C-shaped hyaline cartilage rings to prevent collapse.
• 💪 The posterior wall of the trachea lacks cartilage and is composed of smooth muscle (musculus trachealis), allowing changes in tracheal diameter during breathing.
• 🫀 Blood supply to the trachea comes from the inferior thyroid artery, while venous drainage flows into the inferior thyroid plexus.
• 🧠 The trachea receives sympathetic innervation from the sympathetic trunk and parasympathetic innervation from the vagus and pharyngeal nerves.
• 🦠 The trachea bifurcates into the right and left primary bronchi at the level of the 4th or 5th thoracic vertebrae, with the right bronchus being shorter, wider, and more vertical.
• 🌬 Each primary bronchus branches into secondary (lobar) bronchi, which correspond to the lung lobes (3 in the right lung, 2 in the left).
• 🔬 The terminal bronchioles mark the end of the conducting zone, leading to respiratory bronchioles and eventually alveoli, where gas exchange occurs.

Q & A

What is the anatomical location of the trachea?

The trachea extends from the cricoid cartilage to the jugular notch, situated in front of the esophagus. In adults, the trachea is approximately 11.25 cm long and 2.5 cm in diameter, while in infants, it measures about 4-5 cm long with a diameter of 3 mm.

What is the primary function of the trachea in the respiratory system?

The trachea serves as part of the conduction zone of the respiratory system, whose main function is to conduct air to the lungs.

How is the trachea structurally divided in terms of its skeletal anatomy?

The trachea is structurally divided into two parts: the cervical trachea, located in the neck, and the thoracic trachea, located in the chest.

What is the composition of the tracheal wall?

The lateral and anterior walls of the trachea are composed of C-shaped hyaline cartilage rings, called tracheal cartilage, connected by dense connective tissue. The posterior wall lacks cartilage and is made of smooth muscle and elastic tissue, which allows changes in tracheal diameter during breathing.

What is bifurcation of the trachea, and where does it occur?

The bifurcation of the trachea, also called the carina, occurs at the level of the 4th or 5th thoracic vertebra, where the trachea divides into the left and right primary bronchi.

What are the differences between the right and left primary bronchi?

The right primary bronchus is shorter, wider, and more vertical, while the left primary bronchus is longer, narrower, and more horizontal. These structural differences make foreign objects more likely to enter the right bronchus.

What is the blood supply and venous drainage of the trachea?

The trachea receives arterial blood supply from the inferior thyroid artery, while venous drainage occurs through the inferior thyroid veins into the venous plexus.

How is the trachea innervated?

The trachea receives sympathetic innervation from the sympathetic nervous system and parasympathetic innervation from the vagus nerve and pharyngeal nerves. These systems work antagonistically to control smooth muscle and mucus gland activity.

What are the lymphatic drainage pathways for the trachea?

Lymphatic drainage from the trachea flows into the pretracheal, paratracheal, and cervical lymph nodes.

What is the sequence of branching in the lower respiratory tract after the trachea?

After the trachea, the sequence includes the primary bronchi, secondary (lobar) bronchi, tertiary (segmental) bronchi, bronchioles, terminal bronchioles (last part of the conduction zone), respiratory bronchioles, alveolar ducts, and finally, alveoli.